diff --git a/7.1.155 b/7.1.155
new file mode 100644
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--- /dev/null
+++ b/7.1.155
@@ -0,0 +1,53 @@
+To: vim-dev@vim.org
+Subject: Patch 7.1.155
+Fcc: outbox
+From: Bram Moolenaar <Bram@moolenaar.net>
+Mime-Version: 1.0
+Content-Type: text/plain; charset=ISO-8859-1
+Content-Transfer-Encoding: 8bit
+------------
+
+Patch 7.1.155
+Problem:    Crash when 'undolevels' is 0 and repeating "udd". (James Vega)
+Solution:   When there is only one branch use u_freeheader() to delete it.
+Files:	    src/undo.c
+
+
+*** ../vim-7.1.154/src/undo.c	Mon Oct  1 22:53:27 2007
+--- src/undo.c	Sat Nov 10 13:45:28 2007
+***************
+*** 1677,1682 ****
+--- 1677,1690 ----
+      u_header_T	    **uhpp;	/* if not NULL reset when freeing this header */
+  {
+      u_header_T	    *tofree, *next;
++ 
++     /* If this is the top branch we may need to use u_freeheader() to update
++      * all the pointers. */
++     if (uhp == buf->b_u_oldhead)
++     {
++ 	u_freeheader(buf, uhp, uhpp);
++ 	return;
++     }
+  
+      if (uhp->uh_alt_prev != NULL)
+  	uhp->uh_alt_prev->uh_alt_next = NULL;
+*** ../vim-7.1.154/src/version.c	Thu Nov  8 21:23:34 2007
+--- src/version.c	Sat Nov 10 22:49:40 2007
+***************
+*** 668,669 ****
+--- 668,671 ----
+  {   /* Add new patch number below this line */
++ /**/
++     155,
+  /**/
+
+-- 
+I AM THANKFUL...
+...for the piles of laundry and ironing because it means I
+have plenty of clothes to wear.
+
+ /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
+///        sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
+\\\        download, build and distribute -- http://www.A-A-P.org        ///
+ \\\            help me help AIDS victims -- http://ICCF-Holland.org    ///